TWI585041B - Aluminosilicate, metal ion absorbent, and method for producing these - Google Patents

Description

Aluminosilicate, metal ion adsorbent and method for producing same

The present invention relates to an aluminosilicate, a metal ion adsorbent, and a process for the preparation thereof.

In recent years, it has been desired to remove harmful substances such as free residual chlorine contained in drinking water. Further, there are still many examples in which a lead-containing material is used as a water pipe, and a water purifier having excellent removal performance of heavy metal ions is highly desired.

As an activated carbon molded body for removing heavy metals, for example, Japanese Laid-Open Patent Publication No. 2003-334543 discloses a fine inorganic compound having a particle diameter of 0.1 μm to 90 μm containing fibrous activated carbon and having heavy metal adsorption performance. An activated carbon molded body formed by mixing a mixture of adhesives. In the activated carbon molded body, an aluminosilicate zeolite is used as the fine particulate inorganic compound.

In addition, industrial wastes such as general industrial wastes, solvent manufacturing wastes, and synthetic rubber manufacturing wastes, and removal of heavy metal compounds contained in various research facilities, medical wastes, and household wastes, for example, are patented in Japan. Japanese Laid-Open Patent Publication No. 2000-342962 discloses a compound bond of one or more kinds of porous substances selected from a group consisting of activated carbon, zeolite, diatomaceous earth, natural sand, and ceramics with a chelate-forming group. A heavy metal adsorbent that is formed.

In view of the above circumstances, an object of the present invention is to provide an aluminosilicate having excellent adsorptivity of metal ions and a metal having the aluminosilicate as a component. Ion sorbents and methods for their preparation.

The present invention encompasses the following aspects.

<1> An aluminosilicate having an elemental ratio of Si and Al of 0.3 to 1.0 in terms of a molar ratio of Si/Al, a peak near 3 ppm in a ²⁷ Al-NMR spectrum, and a ²⁹ Si-NMR spectrum in a ²⁹ Si-NMR spectrum. There is a peak near -78 ppm and around -85 ppm, and a peak in the powder X-ray diffraction spectrum using CuKα ray as an X-ray source at 2θ=26.9° and 40.3°, and near -78 ppm in the ²⁹ Si-NMR spectrum. The area ratio (peak B/peak A) of the peak A and the peak B near -85 ppm is 2.0 to 9.0.

<2> An aluminosilicate having an elemental ratio of Si and Al of 0.3 to 1.0 in terms of a molar ratio of Si/Al, a ²⁷ Al-NMR spectrum having a peak near 3 ppm, and a ²⁹ Si-NMR spectrum at around -78 ppm and There is a peak near -85 ppm, and the powder X-ray diffraction spectrum using CuKα ray as an X-ray source has a peak near 2θ=26.9° and 40.3°, and is in a Transmission Electron Microscopy (TEM) photograph. When observed at 100,000 times, there was no tube having a length of 50 nm or more.

<3> The aluminosilicate according to the above <1>, wherein when viewed in a transmission electron microscope (TEM) photograph at 100,000 times, a tubular having a length of 50 nm or more is not present.

The aluminosilicate of any one of the above-mentioned <1> to <3>, wherein the Brunauer-Emmett-Teller (BET) specific surface area is 250 m ² /g or more, the total pore volume It is 0.1 cm ³ /g or more and the average pore diameter is 1.5 nm or more.

<5> The aluminophthalic acid according to any one of the above <1> to <4> The salt, in the powder X-ray diffraction spectrum, has peaks in the vicinity of 2θ = 18.8°, 20.3°, 27.8°, 40.6° and 53.3°.

<6> A metal ion adsorbent which comprises aluminosilicate as a component, and the aluminosilicate is an element of Si and Al which is 0.3 to 1.0 in terms of molar ratio of Si/Al in a ²⁷ Al-NMR spectrum. An aluminosilicate having a peak near 3 ppm and having a peak near -78 ppm and around -85 ppm in a ²⁹ Si-NMR spectrum.

<7> The metal ion adsorbent according to the above <6>, wherein an area ratio of a peak A near -78 ppm and a peak B near -85 ppm in the ²⁹ Si-NMR spectrum of the aluminosilicate (peak B/) The peak A) is 2.0 to 9.0.

The metal ion adsorbent according to the above <6> or <7>, wherein the aluminosilicate is not observed in a transmission electron microscope (TEM) image at a ratio of 50 nm or more when observed at 100,000 times. The aluminum citrate of the tube.

The metal ion adsorbent according to any one of the above-mentioned <6>, wherein the aluminosilicate has a BET specific surface area of 250 m ² /g or more and a total pore volume of 0.1 cm ³ / The above g and the average pore diameter are 1.5 nm or more.

The metal ion adsorbent according to any one of the above-mentioned <6>, wherein the aluminosilicate is in a powder X-ray diffraction spectrum using CuKα ray as an X-ray source at 2θ. Aluminosilicate having a peak near 26.9° and 40.3°.

<11> The metal ion adsorbent according to the above <10>, wherein The aluminosilicate has a peak in the powder X-ray diffraction spectrum at 2θ = 18.8°, 20.3°, 27.8°, 40.6° and 53.3°.

The method for producing an aluminosilicate according to any one of the above <1> to <5>, comprising the steps of: (a) mixing a solution containing ceric acid ions and a solution containing aluminum ions to obtain a reaction product; (b) performing desalting and solid separation of the above reaction product; (c) in an aqueous medium, in the presence of an acid, Heat-treating the solids separated in the above step (b) with a concentration of cesium atoms of 100 mmol/L or more and an atomic concentration of aluminum of 100 mmol/L or more; and (d) pairing in the above step (c) The heat treatment is carried out to obtain the desalting and solid separation.

<13> The method for producing an aluminosilicate according to the above <12>, wherein the conductivity in the case of dispersing in water at a concentration of 60 g/L in the step of the solid separation in the above step (b) is 4.0. Below S/m.

<14> The method for producing an aluminosilicate according to the above <12>, wherein the step (c) is a step of adjusting the pH to 3 or more and less than 7, and at a temperature of 80 to 160 ° C. The step of heat treatment is performed within a period of 96 hours or less.

The method for producing an aluminosilicate according to any one of the above aspects, wherein the (a) step is a cesium atom concentration of the solution containing the ceric acid ion of 100 mmol/L. As described above, the aluminum atom-containing solution has a concentration of aluminum atom of 100 mmol/L or more, and lanthanum is a step of mixing the element of aluminum with respect to Si/Al in a molar ratio of 0.3 to 1.0.

The method for producing an aluminosilicate according to any one of the above aspects, wherein the step (b) includes the step of dispersing the reaction product in an aqueous medium to obtain a dispersion. And a step of adjusting the pH of the above dispersion to 5 to 7 and performing solid separation.

The method for producing a metal ion adsorbent according to any one of the above aspects, comprising the step of: (a) mixing a solution containing phthalic acid ions and a solution containing aluminum ions; And obtaining the reaction product; (b) performing desalting and solid separation of the above reaction product; (c) heat-treating the solid separated in the above step (b) in the presence of an acid in an aqueous medium; And (d) performing desalting and solid separation on the obtained heat treatment in the above step (c).

<18> The method for producing a metal ion adsorbent according to the above <17>, wherein the heat treatment in the step (c) is a concentration of germanium atoms in an aqueous medium of 100 mmol/L or more and an aluminum atom concentration of 100 mmol/ It is carried out under the conditions of L or higher.

The method for producing a metal ion adsorbent according to the above <17>, wherein the solid separation in the step (b) is carried out in a concentration of 60 g/L. The electrical conductivity is 4.0 S/m or less.

The method for producing a metal ion adsorbent according to any one of the above aspects, wherein the step (c) is to adjust the pH to 3 or more, less than 7, and the temperature to 80 ° C. The step of heat treatment was carried out at 160 ° C for a period of not more than 96 hours.

<21> The metal according to any one of <17> to <20> above In the method for producing an ion adsorbent, the step (a) is such that the concentration of the ruthenium atom of the solution containing the ruthenic acid ion is 100 mmol/L or more, and the concentration of the aluminum atom of the solution containing the aluminum ion is 100 mmol/L or more. The element of aluminum is a method in which the above-described solution containing ceric acid ions and a solution containing aluminum ions are mixed in such a manner that the Si/Al ratio is 0.3 to 1.0 in terms of a molar ratio.

The method for producing a metal ion adsorbent according to any one of the above aspects, wherein the step (b) includes the step of dispersing the reaction product in an aqueous medium to obtain a dispersion. And a step of adjusting the pH of the above dispersion to 5 to 7 and performing solid separation.

According to the present invention, it is possible to provide an aluminosilicate having excellent metal ion adsorption properties, a metal ion adsorbent having the aluminosilicate as a component, and a method for producing the same.

In the present specification, the term "step" is not only an independent step, but is also included in the term as long as the intended effect of the step is achieved even if it cannot be clearly distinguished from other steps. In addition, in the present specification, the numerical range indicated by "~" indicates a range in which the numerical values described before and after the "~" are included as the minimum value and the maximum value. Further, in the present specification, when the amount of each component in the composition is such that a plurality of substances corresponding to the respective components are present in the composition, unless otherwise specified, it means the plurality of substances present in the composition. Total amount.

<aluminum silicate>

The elemental Si and Al of the aluminosilicate according to the first embodiment of the present invention have a molar ratio of 0.3 to 1.0 in terms of a molar ratio of Si/Al, and a peak in the vicinity of 3 ppm in a ²⁷ Al-NMR spectrum, at ²⁹ Si- In the NMR spectrum, there were peaks in the vicinity of -78 ppm and in the vicinity of -85 ppm, and peaks in the powder X-ray diffraction spectrum using CuKα rays as the X-ray source in the vicinity of 2θ=26.9° and 40.3°. Further, it is an area ratio (peak B/peak A) of the peak A near -78 ppm and the peak B near -85 ppm in the ²⁹ Si-NMR spectrum of 2.0 to 9.0, or in a transmission electron microscope (TEM). When the photograph was observed at 100,000 times in the photograph, there was no aluminosilicate having a tubular body having a length of 50 nm or more.

The aluminosilicate of the first embodiment has a peak in the vicinity of 2θ=26.9° and 40.3° in the powder X-ray diffraction spectrum. Powder X-ray diffraction is performed using CuKα rays as an X-ray source. For example, a powder X-ray diffraction apparatus manufactured by Rigaku Co., Ltd.: Geigerflex RAD-2X (trade name) can be used.

Fig. 1 shows a powder X-ray diffraction spectrum of the aluminosilicate of Production Example 1 which will be described later as an example of the aluminosilicate of the first embodiment. For comparison, a powder X-ray diffraction spectrum of the aluminosilicate of Production Example 2, which is called so-called filamentous aragonite, is also disclosed in FIG.

As shown in Fig. 1, the aluminosilicate of the first embodiment has a peak in the vicinity of 2θ = 26.9 ° and 40.3 ° in the powder X-ray diffraction spectrum. It is estimated that the peak near 2θ=26.9° and 40.3° is the peak derived from the aluminum silicate of the first embodiment.

The specific aluminosilicate of the first embodiment does not have a broad peak in the vicinity of 2θ=20° and 35° in the powder X-ray diffraction spectrum. Can be considered 2θ The peaks near =20° and 35° are peaks of reflection from the hk0 plane of the low-crystalline layered clay mineral.

Here, the fact that there is no peak near 2θ=20° and 35° means that the displacement from the baseline near 2θ=20° and 35° is below the noise level, specifically, the displacement from the baseline is Less than 100% of the noise width.

Further, the aluminosilicate of the first embodiment may have a peak in the vicinity of 2θ = 18.8°, 20.3°, 27.8°, 40.6°, and 53.3°. It is inferred that the peaks in the vicinity of 2θ = 18.8°, 20.3°, 27.8°, 40.6°, and 53.3° are peaks derived from aluminum hydroxide as a by-product. In the method for producing aluminosilicate described later, the heating temperature during the heat treatment is 160° C. or lower, whereby precipitation of aluminum hydroxide can be suppressed. Further, the content of aluminum hydroxide can be adjusted by adjusting the pH at the time of the desalination treatment by centrifugation.

Further, the aluminosilicate of the first embodiment has an elemental ratio of Si and Al of from 0.3 to 1.0, preferably from 0.4 to 0.6, more preferably from 0.4 to 0.6, in terms of molar ratio of Si/Al. Good is 0.45~0.55. When the Si/Al ratio is less than 0.3 in terms of the molar ratio, the amount of Al which does not contribute to the adsorption performance of the aluminum silicate is excessive, and if it exceeds 1.0, the Si which does not contribute to the adsorption performance of the aluminum silicate is not provided. The amount is easy to become excessive.

The elemental ratio of Si and Al can be measured by a conventional method using an Inductively Coupled Plasma (ICP) luminescence spectroscopic device (for example, ICP luminescence spectrometer manufactured by Hitachi, Ltd.: P-4010).

The aluminosilicate of the first embodiment has a peak in the vicinity of 3 ppm in the ²⁷ Al-NMR spectrum. As the ²⁷ Al-NMR measuring device, for example, an AV400WB type manufactured by Bruker BioSpin can be used, and specific measurement conditions are as follows.

Resonance frequency: 104MHz

Determination method: Magic Angle Spinning (MAS) (single pulse)

MAS speed: 10kHz

Measurement area: 52 kHz

Data points: 4096

Resolution (measurement area / data points): 12.7 Hz

Pulse width: 3.0μsec

Delay time: 2 seconds

Chemical shift value benchmark: α-alumina 3.94ppm

Window function: exponential function

Line Broadening factor: 10Hz

Fig. 2 shows a ²⁷ Al-NMR spectrum of the aluminosilicate of Production Example 1 which will be described later as an example of the aluminosilicate of the first embodiment. For comparison, the ²⁷ Al-NMR spectrum of the aluminosilicate of Production Example 2, which is called so-called filamentous aragonite, is also disclosed in FIG.

As shown in Fig. 2, the aluminosilicate of the first embodiment had a peak in the vicinity of 3 ppm in the ²⁷ Al-NMR spectrum. It is inferred that the peak near 3 ppm is a peak derived from 6-coordinated Al. Further, it is also possible to have a peak near 55 ppm. It is inferred that the peak near 55 ppm is the peak derived from the 4-coordinated Al.

The aluminosilicate of the first embodiment preferably has an area ratio of a peak near 55 ppm to a peak near 3 ppm in a ²⁷ Al-NMR spectrum of 25% or less, more preferably 20% or less, and still more preferably 15%. the following.

Further, in view of metal ion adsorption property and metal ion selectivity, the specific aluminosilicate of the first embodiment is preferably an area ratio of a peak near 55 ppm to a peak near 3 ppm in a ²⁷ Al-NMR spectrum. It is 1% or more, more preferably 5% or more, and still more preferably 10% or more.

The aluminosilicate of the first embodiment has a peak in the vicinity of -78 ppm and around -85 ppm in the ²⁹ Si-NMR spectrum. As the ²⁹ Si-NMR measurement device, for example, an AV400WB type manufactured by Bruker BioSpin can be used, and specific measurement conditions are as follows.

Resonance frequency: 79.5MHz

Determination method: MAS (single pulse)

MAS speed: 6kHz

Measurement area: 24 kHz

Number of data points: 2048

Resolution (measurement area / data points): 5.8 Hz

Pulse width: 4.7μsec

Delay time: 600 seconds

Chemical shift value reference: TMSP-d ₄ (3-(trimethylsulfonyl) (2,2,3,3- ² H ₄ )propionate) 1.52 ppm

Window function: exponential function

Line broadening factor: 50Hz

Fig. 3 shows a ²⁹ Si-NMR spectrum of the aluminosilicate of Production Example 1 which will be described later as an example of the aluminosilicate of the first embodiment. For comparison, the ²⁹ Si-NMR spectrum of the aluminosilicate of Production Example 2, which is called so-called filamentous aragonite, is also disclosed in FIG.

As shown in Fig. 3, the aluminosilicate of the first embodiment has a peak in the vicinity of -78 ppm and around -85 ppm in the ²⁹ Si-NMR spectrum. It is considered that the peak A which appears in the vicinity of -78 ppm is an aluminosilicate derived from a crystal structure such as a filamentous aluminite or an aluminite, and is derived from the structure of HO-Si-(OAl) ₃ . Further, it is considered that the peak B which appears in the vicinity of -85 ppm is an aluminosilicate derived from a clay structure or an aluminosilicate having an amorphous structure. Therefore, it is presumed that the aluminosilicate of the first embodiment is a mixture or composite of a crystal structure of aluminosilicate and a clay structure or an amorphous structure of aluminosilicate.

Further, the aluminosilicate of the first embodiment is an aluminosilicate: the area ratio (peak B/peak A) of the peak A near -78 ppm and the peak B near -85 ppm in the ²⁹ Si-NMR spectrum is 2.0 to 9.0, or a tube having a length of 50 nm or more when observed at 100,000 times in a transmission electron microscope (TEM) photograph.

And the area ratio when ²⁹ Si-NMR spectrum of the peaks, in the first ²⁹ Si-NMR spectra Videos baseline. In Fig. 3, a line connecting -55 ppm and -140 ppm is set as a baseline.

Next, the chemical shift value (in the vicinity of -81 ppm in Fig. 3) corresponding to the peak appearing in the vicinity of -78 ppm and the peak near -85 ppm was divided.

In Fig. 3, the area of the peak A near -78 ppm is the area of the area orthogonal to the chemical shift axis and surrounded by a straight line of -81 ppm and the above-mentioned baseline, and the area of the peak B is orthogonal to the chemical shift axis. -81 The area of the line of ppm and the area enclosed by the above baseline.

Furthermore, the area of each of the above peaks can also be obtained by the analysis software incorporated in the NMR measurement apparatus.

The area ratio of the peak B/peak A obtained from the area of the peak A and the peak B obtained as described above is preferably 2.0 to 9.0, 2.0 to 7.0, and more preferably from the viewpoint of improving the adsorption performance of the metal ion. 2.0 to 5.0, and more preferably 2.0 to 4.0.

In addition, when the fiber of the so-called filamentous aluminite which is a tubular aluminosilicate is observed by a transmission electron microscope (TEM) photograph, the area of the peak B is small.

Fig. 4 shows an example of a transmission electron microscope (TEM) photograph of aluminosilicate. The aluminosilicate shown in Fig. 4 is an aluminosilicate of Production Example 1 to be described later. For comparison, FIG. 5 shows a transmission electron microscope (TEM) photograph of a tubular aluminosilicate, that is, an aluminosilicate of Production Example 2 called so-called filiform aragonite. As shown in Fig. 4, when the aluminosilicate of the first embodiment was observed at 100,000 times under a transmission electron microscope (TEM), a tubular having a length of 50 nm or more was not present.

Transmission electron microscopy (TEM) observation of aluminosilicate was carried out at an accelerating voltage of 100 kV. In addition, as a sample to be observed, a solution after heating in a second washing step (desalting and solid separation) in a production method to be described later is applied dropwise to a support for preparing a TEM observation sample, followed by drying to form a sample. A sample of the film. In addition, when the contrast of the TEM image cannot be sufficiently obtained, the observation sample is prepared by appropriately diluting the solution after the heat treatment so that the contrast can be sufficiently obtained.

First embodiment aluminosilicate to improve metal ion adsorption properties viewpoint, preferred is a BET specific surface area of 200m ² / g or more, more preferably 250m ² / g or more, and further more preferably 280m ² / g or more. Further, the upper limit of the BET specific surface area is not particularly limited, but a part of Si in the aluminosilicate is bonded to a part of Al in the form of Si-O-Al, and it contributes to an improvement in the adsorption property of the metal ion. viewpoint, preferably a BET specific surface area of 1500m ² / g or less, more preferably 1200m ² / g or less, and further more preferably 1000m ² / g or less.

The BET specific surface area of the aluminosilicate is determined based on JIS Z 8830 and based on nitrogen adsorption performance. As the evaluation device, for example, QUANTACHROME company: AUTOSORB-1 (trade name) or the like can be used. When the measurement of the BET specific surface area is carried out, it is considered that the moisture adsorbed on the surface of the sample and the structure affects the gas adsorption performance. Therefore, the pretreatment for removing moisture by heating is first performed.

In the above pretreatment, the measurement unit to which 0.05 g of the measurement sample was placed was decompressed to 10 Pa or less by a vacuum pump, and then heated at 110 ° C for 3 hours or more, and then maintained under reduced pressure and naturally cooled. Until normal temperature (25 ° C). After the pretreatment, the evaluation temperature was 77 K, and the evaluation pressure range was measured as a relative pressure (balance pressure with respect to the saturated vapor pressure) to be less than 1.

First embodiment aluminosilicate to improve metal ion adsorption properties viewpoint, preferably the total pore volume of 0.1cm ³ / g or more, more preferably 0.12cm ³ / g or more, and further more preferably 0.15 cm ³ /g or more. In addition, the upper limit of the total pore volume is not particularly limited, but a part of Si in the aluminosilicate is bonded to a part of Al in the form of Si-O-Al, and it contributes to the improvement of the adsorption property of the metal ion. From the viewpoint of the above, the total pore volume is preferably 1.5 cm ³ /g or less, more preferably 1.2 cm ³ /g or less, still more preferably 1.0 cm ³ /g or less.

The total pore volume of the aluminosilicate is based on the above BET specific surface area, and the data obtained by the relative pressure of 0.95 or more and less than 1 is converted into a liquid by the relative pressure of the gas closest to 1. Find out.

The aluminum silicate of the first embodiment preferably has an average pore diameter of 1.5 nm or more, more preferably 1.7 nm or more, and still more preferably 2.0 nm or more from the viewpoint of improving the adsorption performance of metal ions. In addition, the upper limit of the total pore volume is preferably 50 nm or less, more preferably 20 nm or less, and still more preferably 5.0 nm or less from the viewpoint of improving the adsorption performance of the metal ions.

The average pore diameter of the aluminosilicate is determined based on the BET specific surface area and the total pore volume, assuming that all the pores are formed by one cylindrical pore.

<Method for producing aluminum citrate>

The aluminosilicate which is the first embodiment of the present invention can be produced by the following production method.

The method for producing an aluminosilicate of the present invention comprises the steps of: (a) mixing a solution containing a ceric acid ion and a solution containing aluminum ions to obtain a reaction product; (b) performing desalting and solidification of the above reaction product. a step of separating; (c) separating the solid in the above step (b) in the presence of an acid in the presence of an acid at a concentration in which the concentration of germanium atoms is 100 mmol/L or more and the concentration of aluminum atoms is 100 mmol/L or more. a step of heat treatment by the creator; and (d) heating of the above step (c) The treatment is carried out to obtain the steps of desalting and solid separation; and other steps may be included as needed.

After desalination treatment of the coexisting ions from a solution containing a reaction product of citric acid ions and aluminum ions, heat treatment is carried out in the presence of an acid at a higher concentration than when a so-called filamentous aragonite is produced. This makes it possible to efficiently produce an aluminosilicate having excellent metal ion adsorption performance.

It can be considered, for example, as follows. In general, if a heat treatment of the aluminosilicate in the presence of an acid is carried out using a dilute solution, a regular tubular aluminosilicate having a regular structure is formed. However, under the high concentration conditions of the production method of the present invention, it is considered that an aluminosilicate having a clay structure and an amorphous structure in addition to a regular partial structure is formed. It is considered that the aluminosilicate exhibits excellent metal ion adsorption performance by having various structures as described above. Therefore, it is presumed that the aluminosilicate of the first embodiment is an aluminosilicate in which a plurality of structures described above are formed instead of a tubular body having a length of 50 nm or more.

(a) Step of obtaining a reaction product

In the step of obtaining a reaction product, a solution containing phthalic acid ions is mixed with a solution containing aluminum ions to obtain a mixed solution containing an aluminosilicate and a coexisting ion as a reaction product.

(Citrate ion and aluminum ion)

When aluminosilicate is synthesized, the raw material requires citric acid ions and aluminum ions. The citric acid source constituting the solution containing citric acid ions (hereinafter also referred to as "tannic acid solution") is not particularly limited as long as it is produced by solvation during solvation. For example, a tetraalkoxy decane such as sodium orthosilicate, sodium metasilicate or tetraethoxy decane may be mentioned, but it is not limited thereto.

In addition, the aluminum source constituting the solution containing aluminum ions (hereinafter also referred to as "aluminum solution") is not particularly limited as long as it generates aluminum ions when solvated. For example, aluminum chloride, aluminum perchlorate, aluminum nitrate, second butadiene alumina, etc. are mentioned, but it is not limited to these.

As the solvent, those which are easily solvated with a tannic acid source and an aluminum source which are raw materials can be suitably selected and used. Specifically, water, ethanol, or the like can be used. Water is preferably used for the reduction of coexisting ions in the solution during the heat treatment and the ease of handling.

(mixing ratio and concentration of solution)

After the raw materials are separately dissolved in a solvent to prepare a raw material solution (tannic acid solution and aluminum solution), the raw material solutions are mixed with each other to obtain a mixed solution. The element ratio of Si and Al in the mixed solution is higher than that of Si/Al in the aluminum silicate obtained by the Si/Al control, and is adjusted to 0.3 to 1.0 in terms of molar ratio, preferably adjusted to 0.4. ~0.6, better adjusted to 0.45~0.55. By setting the element ratio Si/Al to 0.3 to 1.0, it is easy to synthesize an aluminosilicate having a desired regular structure.

Further, in the case of mixing the raw material solutions, it is preferred to slowly add a citric acid solution to the aluminum solution. By doing so, it is possible to suppress the polymerization of citric acid which may become a factor that hinders the formation of a desired aluminosilicate.

The cesium atom concentration of the citric acid solution is not particularly limited. It is preferably 100 mmol/L to 1000 mmol/L.

When the ruthenium atom concentration of the ruthenium acid solution is 100 mmol/L or more, the productivity is improved, and the aluminosilicate can be efficiently produced. In addition, if the cerium atom concentration of the ceric acid solution is 1000 mmol/L or less, the productivity corresponds to the citric acid solution. The atomic concentration of helium is further increased.

The aluminum atom concentration of the aluminum solution is not particularly limited. It is preferably 100 mmol/L to 1000 mmol/L.

When the aluminum atom concentration of the aluminum solution is 100 mmol/L or more, the productivity is improved, and the aluminosilicate can be efficiently produced. Further, when the aluminum atom concentration of the aluminum solution is 1000 mmol/L or less, the productivity is further improved in accordance with the aluminum atom concentration of the aluminum solution.

(b) First cleaning step (desalting and solid separation)

Mixing a solution containing phthalic acid ions with a solution containing aluminum ions to form a co-existing ion-containing aluminosilicate as a reaction product, and performing desalting and solid separation of the generated aluminosilicate containing coexisting ions The first cleaning step. In the first washing step, at least a portion of the coexisting ions are removed from the mixed solution to reduce the concentration of the coexisting ions in the mixed solution. By performing the first washing step, it is easy to form an aluminosilicate having a desired regular structure in the synthesis step.

In the first washing step, the method of performing desalting and solid separation may be an anion other than a citrate ion derived from a citric acid source and an aluminum source (for example, a chloride ion or a nitrate ion) and a cation other than an aluminum ion (for example, At least a part of the sodium ion is removed (desalt) and the solid is separated, and is not particularly limited. Examples of the first washing step include a method using centrifugation, a method using a dialysis membrane, a method using an ion exchange resin, and the like.

The first washing step is preferably performed such that the concentration of the coexisting ions is equal to or lower than a predetermined concentration. Specifically, for example, it is preferred to separate the solid obtained in the first washing step to a concentration of 60 g/L. When the dispersion is in pure water, the conductivity of the dispersion is 4.0 S/m or less, and more preferably, the conductivity of the dispersion is 1.0 mS/m or more and 3.0 S/m or less. Further, it is more preferable that the conductivity of the dispersion is 1.0 mS/m or more and 2.0 S/m or less.

When the conductivity of the dispersion is 4.0 S/m or less, it tends to form a desired aluminosilicate more easily in the synthesis step.

Further, the electrical conductivity was measured at a normal temperature (25 ° C) using a general conductivity meter: 9382-10D manufactured by HORIBA Corporation: F-55 and the company.

The first washing step preferably includes a step of dispersing the aluminosilicate in an aqueous medium to obtain a dispersion, and a step of adjusting the pH of the dispersion to 5 to 7 and depositing aluminum citrate.

For example, when the first washing step is performed using centrifugation, it can be carried out as follows. A base or the like is added to the mixed solution to adjust the pH to 5 to 7. After the pH-adjusted solution was centrifuged, the supernatant solution was discharged to separate the solid as a gel-like precipitate. Then, the solid separated product was dispersed again in the solvent. At this time, it is preferable to return to the volume before the centrifugal separation. The dispersion liquid formed by dispersing the solid by separation is centrifuged in the same manner, and the operations of desalting and solid separation are repeated, whereby the concentration of the coexisting ions can be made equal to or lower than a predetermined concentration.

In the first washing step, the pH is adjusted to, for example, 5 to 7, but preferably 5.5 to 6.8, more preferably 5.8 to 6.5. The base used for pH adjustment is not particularly limited. For example, sodium hydroxide, ammonia, or the like is preferred.

Further, the conditions of the centrifugal separation are appropriately selected in accordance with the scale of manufacture, the container to be used, and the like. For example, it can be set to 1200 G or more and 1 minute to 30 minutes at room temperature. Specifically, for example, when using Suprema 23 manufactured by TOMY Co., Ltd. and the standard rotor NA-16 of the company as a centrifugal separator, it can be set to 3000 rpm (1450 G) or more and 5 minutes to 10 minutes at room temperature.

The solvent in the first washing step can be appropriately selected and used, and it is easy to solvate with the raw material. Specifically, water, ethanol, or the like can be used, but the coexisting ions in the solution during heating synthesis are reduced and treated. In terms of easiness, it is preferred to use water, and it is more preferable to use pure water. Further, when the cleaning is repeated a plurality of times, it is preferable to omit the pH adjustment.

The number of treatments for desalting and solid separation in the first washing step may be appropriately set in accordance with the residual amount of the coexisting ions. For example, it can be set to 1 to 6 times. When the cleaning is repeated about three times, the residual amount of the coexisting ions is reduced to the extent that the desired synthesis of the aluminosilicate is not affected.

The pH measurement at the time of pH adjustment can be measured by a pH meter using a general glass electrode. Specifically, for example, the trade name: MODEL (F-51) manufactured by Horiba, Ltd. can be used.

(c) Synthesis step

In the synthesis step, in the presence of an acid, in the presence of an acid, the concentration of the cesium atom reaches 100 mmol/L or more and the concentration of the aluminum atom reaches 100 mmol/L or more, and the solid is separated in the first washing step. Heat treatment.

In the previous manufacturing method, heating was performed by using a thin solution It is rational to grow aluminosilicate into a tubular shape. In such a conventional manufacturing method, since the heat treatment is performed by using a thin solution, there is a limit to the improvement in productivity. However, by performing the heat treatment under the conditions of the concentration of the ruthenium atom and the aluminum atom at a specific concentration or higher as in the production method of the present invention, it is possible to produce a metal ion having excellent adsorption properties and having a different productivity from the tubular shape. Structure of aluminosilicate.

After the first washing step, the ruthenium atom and the aluminum atom contained in the solid separated body are adjusted to have a predetermined concentration.

In the present invention, the germanium atom concentration is 100 mmol/L or more and the aluminum atom concentration is 100 mmol/L or more. The cesium atom concentration is preferably 120 mmol/L or more and 2000 mmol/L or less, and the aluminum atom concentration is 120 mmol/L or more and 2000 mmol/L or less, and more preferably the cesium atom concentration is 150 mmol/L or more and 1500 mmol/L or less and aluminum atoms. The concentration is 150 mmol/L or more and 1500 mmol/L or less.

When the atomic concentration of germanium is less than 100 mmol/L or the aluminum atomic concentration is less than 100 mmol/L, it may be difficult to obtain a desired aluminosilicate. Further, there is a tendency that the productivity of the aluminosilicate is lowered.

In addition, the argon atom concentration and the aluminum atom concentration are argon atom concentration and aluminum atom concentration after the pH is adjusted to a predetermined range by adding an acidic compound to be described later.

In addition, the argon atom concentration and the aluminum atom concentration are measured by a conventional method using an ICP luminescence spectrometer (for example, ICP luminescence spectrometer manufactured by Hitachi, Ltd.: P-4010).

When the concentration of germanium atoms and the concentration of aluminum atoms reach the above specified concentration When the method is adjusted, a solvent can also be added. The solvent can be appropriately selected and used, and it is easy to solvate with a raw material. Specifically, water, ethanol, or the like can be used. However, in terms of reduction of coexisting ions in the solution during heating synthesis and ease of handling, Good use of water.

In the synthesis step, at least one acidic compound is added prior to the heat treatment. The pH after the addition of the acidic compound is not particularly limited. From the viewpoint of efficiently obtaining a desired aluminosilicate, the pH is preferably 3 or more, less than 7, and more preferably 3 or more and 5 or less.

The acidic compound to be added in the synthesis step is not particularly limited and may be an organic acid or a mineral acid. Among them, it is preferred to use a mineral acid. Specific examples of the inorganic acid include hydrochloric acid, perchloric acid, and nitric acid. In consideration of the decrease in the coexisting ion species in the solution during the heat treatment described later, it is preferred to use an acidic compound which forms the same anion as the anion contained in the aluminum source used.

After the addition of the acidic compound, heat treatment is performed, whereby an aluminosilicate having a desired structure can be obtained.

The heating temperature is not particularly limited. From the viewpoint of efficiently obtaining the desired aluminosilicate, it is preferably from 80 ° C to 160 ° C.

When the heating temperature is 160 ° C or lower, precipitation of diaspore (aluminum hydroxide) tends to be suppressed. Further, when the heating temperature is 80 ° C or higher, the desired synthesis speed of the aluminosilicate is increased, and the desired aluminosilicate is more efficiently produced.

The heating time is not particularly limited. From the viewpoint of obtaining an aluminosilicate having a desired structure more efficiently, it is preferably 96 hours (4 days) Within.

If the heating time is 96 hours or less, the desired aluminosilicate can be produced more efficiently.

(d) Second cleaning step (desalting and solid separation)

In the second washing step, the obtained one of the heat treatment in the synthesis step is subjected to desalting and solid separation. Thereby, an aluminosilicate having excellent metal ion adsorption properties can be obtained. It can be considered, for example, as follows. In other words, in the case where the heat treatment is performed in the synthesis step, the adsorption site of the aluminosilicate is clogged with the coexisting ions, and the desired metal ion adsorption performance cannot be obtained. Therefore, it can be considered that the desalting and solid separation are performed by the second washing step of removing at least a part of the coexisting ions from the aluminosilicate obtained in the synthesis step, whereby aluminum having excellent metal ion adsorption performance can be obtained. Citrate.

The second washing step may be performed by removing at least a portion of the anion other than the citric acid ion and the cation other than the aluminum ion, and may be the same operation as the first washing step before the synthesis step, or may be a different operation.

The second washing step is preferably performed such that the concentration of the coexisting ions is equal to or lower than a predetermined concentration. Specifically, for example, when the solid obtained by separating the solid obtained in the second washing step is dispersed in pure water so as to have a concentration of 60 g/L, the conductivity of the dispersion becomes 4.0 S/ It is preferable that the conductivity of the dispersion is 1.0 mS/m or more and 3.0 S/m or less, and more preferably, the conductivity of the dispersion is 1.0 mS/m or more. It is carried out in a manner of 2.0 S/m or less.

When the conductivity of the dispersion is 4.0 S/m or less, there is a tendency that an aluminosilicate having more excellent metal ion adsorption performance is easily obtained.

When the second washing step is carried out using centrifugation, for example, it can be carried out as follows. A base or the like is added to the mixed solution to adjust the pH to 5 to 10. After the pH-adjusted solution was centrifuged, the supernatant solution was discharged to separate the solid as a gel-like precipitate. Then, the solid separated is dispersed again in the solvent. At this time, it is preferable to return to the volume before the centrifugal separation. The dispersion liquid formed by dispersing the solid by separation is centrifuged in the same manner, and the operations of desalting and solid separation are repeated, whereby the concentration of the coexisting ions can be made equal to or lower than a predetermined concentration.

In the second washing step, the pH is adjusted to, for example, 5 to 10, but preferably 8 to 10. The base used for pH adjustment is not particularly limited. For example, sodium hydroxide, ammonia, or the like is preferred.

Further, the conditions of the centrifugal separation are appropriately selected in accordance with the scale of manufacture, the container to be used, and the like. For example, it can be set to 1200 G or more and 1 minute to 30 minutes at room temperature. Specifically, for example, when using Suprema 23 manufactured by TOMY Co., Ltd. and the standard rotor NA-16 of the company as a centrifugal separator, it can be set to 3000 rpm (1450 G) or more and 5 minutes to 10 minutes at room temperature.

The solvent in the second washing step can be appropriately selected and used, and it is easy to solvate with the raw material. Specifically, water, ethanol, or the like can be used. However, in terms of reduction of coexisting ions and ease of handling, it is preferred. In order to use water, it is more preferable to use pure water. Further, when the cleaning is repeated a plurality of times, it is preferable to omit the pH adjustment.

The number of times of the desalting and solid separation in the second washing step may be set according to the amount of residual ions, but it is preferably one to six times, and if the washing is repeated three times or more, the aluminosilicate The residual amount of the coexisting ions in the medium is sufficiently reduced.

It is preferable that the dispersion liquid after the second washing step has a concentration of chloride ions and sodium ions which are particularly affected by the adsorption performance of the aluminosilicate, among the remaining coexisting ions. That is, the washed aluminosilicate in the second washing step is preferably such that when the aluminosilicate is dispersed in water to prepare an aqueous dispersion having a concentration of 400 mg/L, the concentration is given in the aqueous dispersion. A chloride ion of 100 mg/L or less and a sodium ion of a concentration of 100 mg/L or less. If the chloride ion concentration is 100 mg/L or less and the sodium ion concentration is 100 mg/L or less, the adsorption performance can be further improved. The chloride ion concentration is more preferably 50 mg/L or less, and still more preferably 10 mg/L or less. The sodium ion concentration is more preferably 50 mg/L or less, and still more preferably 10 mg/L or less. The chloride ion concentration and the sodium ion concentration can be adjusted by the number of treatments in the washing step or the type of base used for pH adjustment.

Further, the chloride ion concentration and the sodium ion concentration are measured under normal conditions using an ion chromatograph (for example, DX-320 and DX-100 manufactured by Dionex Corporation).

Further, the concentration of the dispersion of the aluminosilicate is based on the mass of the solid obtained by drying the solid at 110 ° C for 24 hours.

In addition, the "dispersion after the second washing step" as used herein refers to a dispersion in which the volume is returned to the volume before the second washing step by the solvent after the second washing step is completed. The solvent used can be suitably selected and In particular, water, ethanol, or the like can be used for the solvation of the raw material. However, it is preferable to use water for the reduction of the residual amount of the coexisting ions in the aluminosilicate and the ease of handling.

The BET specific surface area of the aluminosilicate can be subjected to a treatment method of the second washing step (for example, a method of repeating one or more times of the following treatment: adding a base to the synthesis solution to adjust the pH to 5 to 10, and performing centrifugation Thereafter, the supernatant solution was discharged, and the aluminosilicate remaining as a gelatinous precipitate was again dispersed in a solvent and then returned to the volume before centrifugation to adjust.

In addition, the total pore volume of the aluminosilicate can be adjusted by the treatment method of the second washing step (for example, by repeating one or more times of the following treatment: adding a base to the synthesis solution to adjust the pH to 5 to 10, After centrifugation, the supernatant solution was discharged, and the aluminosilicate remaining as a gelatinous precipitate was again dispersed in a solvent and then returned to the volume before centrifugation to adjust.

In addition, the average pore diameter of the aluminosilicate may be adjusted by the treatment method of the second washing step (for example, by repeating one or more times of the following treatment: adding a base to the synthesis solution to adjust the pH to 5 to 10, After centrifugation, the supernatant solution was discharged, and the aluminosilicate remaining as a gelatinous precipitate was again dispersed in a solvent and then returned to the volume before centrifugation to adjust.

<Use>

The aluminosilicate of the first embodiment is useful as an adsorbent for metal ions. More specifically, it effectively adsorbs nickel ions, copper ions, and manganese ions. Son and so on.

<Metal ion adsorbent>

The metal ion adsorbent according to the second embodiment of the present invention contains aluminosilicate as a component. The elemental Si and Al of the aluminosilicate of the second embodiment have a molar ratio of 0.3 to 1.0 in terms of a molar ratio of Si/Al, a peak in the vicinity of 3 ppm in the ²⁷ Al-NMR spectrum, and a ²⁹ Si-NMR spectrum in the ²⁹ Si-NMR spectrum. There are peaks near -78 ppm and around -85 ppm.

The aluminum bismuth salt of the second embodiment has an elemental ratio of Si and Al of from 0.3 to 1.0, preferably from 0.4 to 0.6, more preferably from 0.4 to 0.6, in terms of molar ratio of Si/Al. 0.45~0.55. When the Si/Al ratio is less than 0.3 in terms of the molar ratio, the amount of Al which does not contribute to the adsorption performance of the aluminum silicate is excessive, and if it exceeds 1.0, the Si which does not contribute to the adsorption performance of the aluminum silicate is not provided. The amount is easy to become excessive.

The elemental ratio of Si and Al can be measured by a conventional method using an ICP emission spectroscopic device (for example, ICP emission spectrometer manufactured by Hitachi, Ltd.: P-4010).

The aluminosilicate of the second embodiment has a peak in the vicinity of 3 ppm in the ²⁷ Al-NMR spectrum. As the ²⁷ Al-NMR measuring device, for example, an AV400WB type manufactured by Bruker BioSpin can be used, and specific measurement conditions are as follows.

Resonance frequency: 104MHz

Determination method: MAS (single pulse)

MAS speed: 10kHz

Measurement area: 52 kHz

Data points: 4096

Resolution (measurement area / data points): 12.7 Hz

Pulse width: 3.0μsec

Delay time: 2 seconds

Chemical shift value benchmark: α-alumina 3.94ppm

Window function: exponential function

Line broadening factor: 10Hz

Fig. 2 shows a ²⁷ Al-NMR spectrum of the aluminum silicate of Production Example 1 and Production Example 2 which will be described later as an example of the aluminosilicate of the second embodiment.

As shown in Fig. 2, the aluminosilicate of the second embodiment has a peak in the vicinity of 3 ppm in the ²⁷ Al-NMR spectrum. It is inferred that the peak near 3 ppm is a peak derived from 6-coordinated Al. Further, it is also possible to have a peak near 55 ppm. It is inferred that the peak near 55 ppm is the peak derived from the 4-coordinated Al.

The aluminosilicate of the second embodiment preferably has an area ratio of a peak near 55 ppm to a peak near 3 ppm in a ²⁷ Al-NMR spectrum of 25% or less, more preferably 20% or less, and still more preferably 15%. the following.

Further, in view of metal ion adsorption property and metal ion selectivity, the specific aluminosilicate of the present embodiment preferably has an area ratio of a peak near 55 ppm to a peak near 3 ppm in the ²⁷ Al-NMR spectrum. 1% or more, more preferably 5% or more, and still more preferably 10% or more.

The aluminosilicate of the second embodiment has a peak in the vicinity of -78 ppm and around -85 ppm in the ²⁹ Si-NMR spectrum. As the ²⁹ Si-NMR measurement device, for example, an AV400WB type manufactured by Bruker BioSpin can be used, and specific measurement conditions are as follows.

Resonance frequency: 79.5MHz

Determination method: MAS (single pulse)

MAS speed: 6kHz

Measurement area: 24 kHz

Number of data points: 2048

Resolution (measurement area / data points): 5.8 Hz

Pulse width: 4.7μsec

Delay time: 600 seconds

Chemical shift value reference: TMSP-d ₄ (3-(trimethylsulfonyl) (2,2,3,3- ² H ₄ )propionate) 1.52 ppm

Window function: exponential function

Line broadening factor: 50Hz

Fig. 3 shows a ²⁹ Si-NMR spectrum of the aluminum silicate of Production Example 1 and Production Example 2 which will be described later as an example of the aluminosilicate of the second embodiment.

As shown in Fig. 3, the aluminosilicate of the second embodiment has a peak in the vicinity of -78 ppm and around -85 ppm in the ²⁹ Si-NMR spectrum. It can be considered that the peak A which appears in the vicinity of -78 ppm is an aluminosilicate derived from a crystal structure such as a filamentous aragonite or an aluminite, and it can be considered that the peak B which appears near -85 ppm is an aluminum derived from a clay structure. Aluminate or an amorphous structure of aluminosilicate. Therefore, it is presumed that the aluminosilicate of the second embodiment is a mixture or composite of a crystal structure of aluminosilicate and a clay structure or an amorphous structure of aluminosilicate.

The aluminosilicate of the second embodiment is preferably an area ratio of a peak A near -78 ppm and a peak B near -103.8 ppm in a ²⁹ Si-NMR spectrum from the viewpoint of improving the adsorption performance of metal ions (peak) The B/peak A) is 0.4 to 9.0, more preferably 1.5 to 9.0, further preferably 2.0 to 9.0, more preferably 2.0 to 7.0, still more preferably 2.0 to 5.0, and particularly preferably 2.0 to 4.0.

And the area ratio when ²⁹ Si-NMR spectrum of the peaks, in the first ²⁹ Si-NMR spectra Videos baseline. In Fig. 3, a line connecting -55 ppm and -140 ppm is set as a baseline.

Next, the chemical shift value (near -81 ppm in Fig. 3) corresponding to the peak appearing in the vicinity of -78 ppm and the peak near -85 ppm was used.

In Fig. 3, the area of the peak A near -78 ppm is the area of the area orthogonal to the chemical shift axis and surrounded by a straight line of -81 ppm and the above-mentioned baseline, and the area of the peak B is orthogonal to the chemical shift axis. The area of the -81 ppm line and the area enclosed by the above baseline.

Furthermore, the area of each of the above peaks can also be obtained by the analysis software incorporated in the NMR measurement apparatus.

An example of a transmission electron microscope (TEM) photograph of the aluminosilicate of the second embodiment is shown in FIGS. 4 and 5. The aluminosilicate shown in Fig. 4 is an aluminosilicate of Production Example 1 to be described later. The aluminosilicate shown in Fig. 5 is an aluminosilicate of Production Example 2 to be described later.

As shown in FIG. 4, when the aluminosilicate of Production Example 1 was observed at 100,000 times under a transmission electron microscope (TEM), a tubular having a length of 50 nm or more was not present. As shown in FIG. 5, the aluminum silicate of Production Example 2 is a tube. The so-called filamentous aluminite.

Transmission electron microscopy (TEM) observation of aluminosilicate was carried out at an accelerating voltage of 100 kV. In addition, as a sample to be observed, a solution after heating in a second washing step (desalting and solid separation) in a production method to be described later is applied dropwise to a support for preparing a TEM observation sample, followed by drying to form a sample. A sample of the film. In addition, when the contrast of the TEM image cannot be sufficiently obtained, the observation sample is prepared by appropriately diluting the solution after the heat treatment so that the contrast can be sufficiently obtained.

The tubular material shown in FIG. 5 is produced by heat-treating citric acid ions and aluminum ions at a specific concentration or lower in a method for producing an aluminosilicate described later. On the other hand, the aluminosilicate which is not observed as shown in FIG. 4 is produced by subjecting ceric acid ions and aluminum ions to heat treatment at a specific concentration or higher.

Fig. 6 is a view schematically showing a tubular so-called filamentous aragonite as an example of the aluminosilicate of the second embodiment. As shown in Fig. 6, there is a tendency that the fiber structure is formed by the tubular bodies 10a, and the inner wall 20 of the tubular body 10a or the outer wall of the tubular body 10a forming the gap 30 between the tubular bodies 10a (outer circumference) The surface is used as an adsorption site for metal ions. The length of the tubular body 10a in the longitudinal direction of the tube portion is, for example, 1 nm to 10 μm. The tubular body 10a has, for example, a circular tubular shape, and has an outer diameter of, for example, 1.5 nm to 3.0 nm, and an inner diameter of, for example, 0.7 nm to 1.4 nm.

Further, when the fiber of the so-called filamentous aragonite which is a tubular aluminosilicate is observed by a transmission electron microscope (TEM) photograph, the area at the peak B is small in the ²⁹ Si-NMR spectrum. direction.

The aluminosilicate of the second embodiment preferably has a peak in the vicinity of 2θ = 26.9 ° and 40.3 ° in the powder X-ray diffraction spectrum. Powder X-ray diffraction is performed using CuKα rays as an X-ray source. For example, a powder X-ray diffraction apparatus manufactured by Rigaku Co., Ltd.: Geigerflex RAD-2X (trade name) can be used.

Fig. 1 shows a powder X-ray diffraction spectrum of aluminosilicate of Production Example 1 and Production Example 2 which will be described later as an example of the aluminosilicate of the second embodiment.

As shown in Fig. 1, the aluminosilicate of the second embodiment has a peak in the vicinity of 2θ = 26.9 ° and 40.3 ° in the powder X-ray diffraction spectrum. It is inferred that the peak near 2θ=26.9° and 40.3° is a peak derived from aluminosilicate.

Further, as in the case of the aluminosilicate of Production Example 1, the aluminosilicate of the second embodiment has a peak at around 2θ = 18.8°, 20.3°, 27.8°, 40.6°, and 53.3°. It is inferred that the peaks in the vicinity of 2θ = 18.8°, 20.3°, 27.8°, 40.6°, and 53.3° are peaks derived from aluminum hydroxide as a by-product. In the method for producing aluminosilicate described later, the heating temperature during the heat treatment is 160° C. or lower, whereby precipitation of aluminum hydroxide can be suppressed. Further, the content of aluminum hydroxide can be adjusted by adjusting the pH at the time of the desalination treatment by centrifugation.

Further, as in the case of the aluminosilicate of Production Example 2, the aluminosilicate of the second embodiment has a peak in the vicinity of 2θ=4.8°, 9.7°, and 14.0°. Further, it is also possible to have a peak in the vicinity of 2θ = 18.3°. It is estimated that the peaks in the vicinity of 2θ=4.8°, 9.7°, 14.0°, and 18.3° are peaks in which the single fibers derived from the so-called filamentous aluminite as the cylindrical aluminosilicate are collected in parallel to obtain a bundle structure.

The second embodiment aluminosilicate to improve metal ion adsorption properties viewpoint, preferred is a BET specific surface area of 200m ² / g or more, more preferably 250m ² / g or more, and further more preferably 280m ² / g or more. Further, the upper limit of the BET specific surface area is not particularly limited, but a part of Si in the aluminosilicate is bonded to a part of Al in the form of Si-O-Al, and it contributes to an improvement in the adsorption property of the metal ion. The BET specific surface area is preferably 1,500 m ² /g or less, more preferably 1200 m ² /g or less, still more preferably 1,000 m ² /g or less.

The BET specific surface area of the aluminosilicate is determined based on JIS Z 8830 and based on nitrogen adsorption performance. As the evaluation device, for example, QUANTACHROME company: AUTOSORB-1 (trade name) or the like can be used. When the measurement of the BET specific surface area is carried out, it is considered that the moisture adsorbed on the surface of the sample and the structure affects the gas adsorption performance. Therefore, the pretreatment for removing moisture by heating is first performed.

In the above pretreatment, the measurement unit to which 0.05 g of the measurement sample was placed was decompressed to 10 Pa or less by a vacuum pump, and then heated at 110 ° C for 3 hours or more, and then maintained under reduced pressure and naturally cooled. Until normal temperature (25 ° C). After the pretreatment, the evaluation temperature was 77 K, and the evaluation pressure range was measured as a relative pressure (balance pressure with respect to the saturated vapor pressure) to be less than 1.

The second embodiment aluminosilicate to improve metal ion adsorption properties viewpoint, preferably the total pore volume of 0.1cm ³ / g or more, more preferably 0.12cm ³ / g or more, and further more preferably 0.15 cm ³ /g or more. In addition, the upper limit of the total pore volume is not particularly limited, but a part of Si in the aluminosilicate is bonded to a part of Al in the form of Si-O-Al, and it contributes to the improvement of the adsorption property of the metal ion. From the viewpoint of the above, the total pore volume is preferably 1.5 cm ³ /g or less, more preferably 1.2 cm ³ /g or less, still more preferably 1.0 cm ³ /g or less.

The total pore volume of the aluminosilicate is based on the above BET specific surface area, and the data obtained by the relative pressure of 0.95 or more and less than 1 is converted into a liquid by the relative pressure of the gas closest to 1. Find out.

The aluminum silicate of the second embodiment preferably has an average pore diameter of 1.5 nm or more, more preferably 1.7 nm or more, and still more preferably 2.0 nm or more from the viewpoint of improving the adsorption performance of metal ions. In addition, the upper limit of the total pore volume is preferably 50 nm or less, more preferably 20 nm or less, and still more preferably 5.0 nm or less from the viewpoint of improving the adsorption performance of the metal ions.

The average pore diameter of the aluminosilicate is determined based on the BET specific surface area and the total pore volume, assuming that all the pores are formed by one cylindrical pore.

<Method for producing aluminum citrate>

The aluminosilicate which is a component of the metal ion adsorbent of the second embodiment of the present invention can be produced as follows.

The method for producing an aluminosilicate according to the second embodiment includes the steps of: (a) mixing a solution containing ceric acid ions and a solution containing aluminum ions to obtain a reaction product; (b) performing desalting and solidification of the above reaction product. Separating; (c) heat-treating in the presence of an acid in the presence of an acid in the above step (b); and (d) obtaining heat treatment in the above step (c) Desalting and solid separation are carried out; and other steps may be included as needed.

The deionization treatment of the coexisting ions from the solution containing the aluminosilicate as the reaction product is followed by heat treatment in the presence of an acid, whereby the metal ion adsorbent excellent in metal ion adsorption performance can be efficiently produced.

It can be considered, for example, as follows. The aluminosilicate having a regular structure is formed by heat-treating the aluminosilicate having the coexisting ions which have formed the structure which hinders the formation of the rule in the presence of an acid. It is considered that the aluminosilicate can efficiently adsorb metal ions by having a regular structure and having an affinity for metal ions.

(a) Step of obtaining a reaction product

In the step of obtaining a reaction product, a solution containing phthalic acid ions is mixed with a solution containing aluminum ions to obtain a mixed solution containing an aluminosilicate and a coexisting ion as a reaction product.

(Citrate ion and aluminum ion)

When aluminosilicate is synthesized, the raw material requires citric acid ions and aluminum ions. The citric acid source constituting the solution containing citric acid ions (hereinafter also referred to as "tannic acid solution") is not particularly limited as long as it is produced by solvation during solvation. For example, a tetraalkoxy decane such as sodium orthosilicate, sodium metasilicate or tetraethoxy decane may be mentioned, but it is not limited thereto.

In addition, the aluminum source constituting the solution containing aluminum ions (hereinafter also referred to as "aluminum solution") is not particularly limited as long as it generates aluminum ions when solvated. For example, aluminum chloride, aluminum perchlorate, aluminum nitrate, second butadiene alumina, etc. are mentioned, but it is not limited to these.

As the solvent, those which are easily solvated with a tannic acid source and an aluminum source which are raw materials can be suitably selected and used. Specifically, water, ethanol, or the like can be used. Water is preferably used for the reduction of coexisting ions in the solution during the heat treatment and the ease of handling.

(mixing ratio and concentration of solution)

After the raw materials are separately dissolved in a solvent to prepare a raw material solution (tannic acid solution and aluminum solution), the raw material solutions are mixed with each other to obtain a mixed solution. The element ratio of Si and Al in the mixed solution is higher than that of Si/Al in the aluminum silicate obtained by the Si/Al control, and is adjusted to 0.3 to 1.0 in terms of molar ratio, preferably adjusted to 0.4. ~0.6, better adjusted to 0.45~0.55. By setting the element ratio Si/Al to 0.3 to 1.0, it is easy to synthesize an aluminosilicate having a desired regular structure.

Further, in the case of mixing the raw material solutions, it is preferred to slowly add a citric acid solution to the aluminum solution. By doing so, it is possible to suppress the polymerization of citric acid which may become a factor that hinders the formation of a desired aluminosilicate.

The cesium atom concentration of the citric acid solution is not particularly limited. It is preferably 1 mmol/L to 1000 mmol/L.

When the ruthenium atom concentration of the ruthenium acid solution is 1 mmol/L or more, the productivity is improved, and the aluminosilicate can be efficiently produced. Further, when the ruthenium atom concentration of the citric acid solution is 1000 mmol/L or less, the productivity is further improved in accordance with the ruthenium atom concentration of the citric acid solution.

The aluminum atom concentration of the aluminum solution is not particularly limited. It is preferably 100 mmol/L to 1000 mmol/L.

When the aluminum atom concentration of the aluminum solution is 100 mmol/L or more, the productivity is improved, and the aluminosilicate can be efficiently produced. In addition, if the aluminum atom concentration of the aluminum solution is 1000 mmol/L or less, the productivity corresponds to the aluminum source of the aluminum solution. The subconcentration is further increased.

(b) First cleaning step (desalting and solid separation)

Mixing a solution containing phthalic acid ions with a solution containing aluminum ions to form a co-existing ion-containing aluminosilicate as a reaction product, and performing desalting and solid separation of the generated aluminosilicate containing coexisting ions The first cleaning step. In the first washing step, at least a portion of the coexisting ions are removed from the mixed solution to reduce the concentration of the coexisting ions in the mixed solution. By performing the first washing step, the desired aluminosilicate is easily formed in the synthesis step.

In the first washing step, the method of performing desalting and solid separation may be an anion other than a citrate ion derived from a citric acid source and an aluminum source (for example, a chloride ion or a nitrate ion) and a cation other than an aluminum ion (for example, At least a part of the sodium ion is removed (desalt) and the solid is separated, and is not particularly limited. Examples of the first washing step include a method using centrifugation, a method using a dialysis membrane, a method using an ion exchange resin, and the like.

The first washing step is preferably performed such that the concentration of the coexisting ions is equal to or lower than a predetermined concentration. Specifically, for example, when the solid obtained by separating the solid obtained in the first washing step is dispersed in pure water so as to have a concentration of 60 g/L, the conductivity of the dispersion becomes 4.0 S/ It is preferable that the conductivity of the dispersion is 1.0 mS/m or more and 3.0 S/m or less, and more preferably, the conductivity of the dispersion is 1.0 mS/m or more. It is carried out in a manner of 2.0 S/m or less.

If the conductivity of the dispersion is 4.0 S/m or less, it is present in the synthesis step. The tendency to form the desired aluminosilicate is more likely to occur.

Further, the electrical conductivity was measured at a normal temperature (25 ° C) using a general conductivity meter: 9382-10D manufactured by HORIBA Corporation: F-55 and the company.

The first washing step preferably includes a step of dispersing the aluminosilicate in an aqueous medium to obtain a dispersion, a step of adjusting the pH of the dispersion to 5 to 7, and a step of precipitating the aluminum niobate.

For example, when the first washing step is performed using centrifugation, it can be carried out as follows. A base or the like is added to the mixed solution to adjust the pH to 5-8. After the pH-adjusted solution was centrifuged, the supernatant solution was discharged to separate the solid as a gel-like precipitate. The separated solids were again dispersed in a solvent. At this time, it is preferable to return to the volume before the centrifugal separation. The dispersion liquid formed by dispersing the solid by separation is centrifuged in the same manner, and the operations of desalting and solid separation are repeated, whereby the concentration of the coexisting ions can be made equal to or lower than a predetermined concentration.

In the first washing step, the pH is adjusted to, for example, 5 to 8, but preferably 5.5 to 6.8, more preferably 5.8 to 6.5. The base used for pH adjustment is not particularly limited. For example, sodium hydroxide, ammonia, or the like is preferred.

Further, the conditions of the centrifugal separation are appropriately selected in accordance with the scale of manufacture, the container to be used, and the like. For example, it can be set to 1200 G or more and 1 minute to 30 minutes at room temperature. Specifically, for example, when using Suprema 23 manufactured by TOMY Co., Ltd. and the standard rotor NA-16 of the company as a centrifugal separator, it can be set to 3000 rpm (1450 G) or more and 5 minutes to 10 minutes at room temperature.

The solvent in the first washing step can be appropriately selected and used, and it is easy to solvate with the raw material. Specifically, water, ethanol, or the like can be used, but the coexisting ions in the solution during heating synthesis are reduced and treated. In terms of easiness, it is preferred to use water, and it is more preferable to use pure water. Further, when the cleaning is repeated a plurality of times, it is preferable to omit the pH adjustment.

The number of treatments for desalting and solid separation in the first washing step may be appropriately set in accordance with the residual amount of the coexisting ions. For example, it can be set to 1 to 6 times. When the cleaning is repeated about three times, the residual amount of the coexisting ions is reduced to the extent that the desired synthesis of the aluminosilicate is not affected.

The pH measurement at the time of pH adjustment can be measured by a pH meter using a general glass electrode. Specifically, for example, the trade name: MODEL (F-51) manufactured by Horiba, Ltd. can be used.

(c) Synthesis step

In the synthesis step, the solid separation is carried out in the presence of an acid in an aqueous medium in the presence of an acid.

The aluminosilicate-containing solution (dispersion) in which the coexisting ions are reduced in the first washing step is heat-treated in the presence of an acid, whereby an aluminosilicate having a regular structure can be formed.

The synthesis step may be carried out by diluting the solids in the first washing step as a dilute solution, or by separating the solids in the first washing step as a high-concentration solution.

By carrying out the synthesis step in a dilute solution, an aluminosilicate having a structure in which the structure is tubularly stretched (hereinafter, also referred to as "first aluminosilicate") can be obtained. In addition, by performing the synthesis step in a high concentration solution, An aluminosilicate (hereinafter also referred to as "second aluminosilicate") having a clay structure and an amorphous structure in addition to the regular structure can be obtained. Further, it is presumed that the second aluminosilicate is formed by an increase in the formation of a clay structure and an amorphous structure instead of the aluminosilicate which has grown into a tubular body having a length of 50 nm or more.

Each of the first and second aluminosilicates has a specific regular structure, thereby exhibiting excellent metal ion adsorption properties.

As a dilution condition in the case where the first aluminosilicate is obtained in the synthesis step, for example, the concentration of germanium atoms is 20 mmol/L or less and the concentration of aluminum atoms is 60 mmol/L or less. In view of the metal ion adsorption performance, the ruthenium atom concentration is preferably 0.1 mmol/L or more, 10 mmol/L or less, and the aluminum atom concentration is 0.1 mmol/L or more and 34 mmol/L or less, more preferably a ruthenium atom. The concentration is 0.1 mmol/L or more and 2 mmol/L or less, and the aluminum atomic concentration is 0.1 mmol/L or more and 7 mmol/L or less.

By setting the germanium atom concentration to 20 mmol/L or less and the aluminum atom concentration to 60 mmol/L or less, the first aluminosilicate can be efficiently produced.

In addition, as a high concentration condition in the case where the second aluminosilicate is obtained in the synthesis step, for example, the concentration of germanium atoms may be 100 mmol/L or more, and the concentration of aluminum atoms may be 100 mmol/L or more. In view of the metal ion adsorption performance, the germanium atom concentration is preferably 120 mmol/L or more and 2000 mmol/L or less, and the aluminum atom concentration is 120 mmol/L or more and 2000 mmol/L or less, and more preferably the germanium atom concentration is 150 mmol/L or more and 1500 mmol/L or less and the aluminum atomic concentration is 150 mmol/L or more and 1500 mmol/L or less.

By setting the germanium atom concentration to 100 mmol/L or more and the aluminum atom When the concentration is 100 mmol/L or more, the second aluminosilicate can be efficiently produced, and the productivity of the aluminosilicate is also improved.

In addition, the argon atom concentration and the aluminum atom concentration are argon atom concentration and aluminum atom concentration after the pH is adjusted to a predetermined range by adding an acidic compound to be described later.

In addition, the cesium atomic concentration and the aluminum atomic concentration are measured using an ICP luminescence spectrometer (for example, ICP luminescence spectrometer manufactured by Hitachi, Ltd.: P-4010).

When the concentration of the ruthenium atom and the aluminum atom concentration are adjusted to a predetermined concentration, a solvent may be added. The solvent can be appropriately selected and used, and it is easy to be solvated with a raw material. Specifically, water, ethanol, or the like can be used, but in terms of reduction of coexisting ions in the solution during heat treatment and ease of handling, Good use of water.

In the synthesis step, at least one acidic compound is added prior to the heat treatment. The pH after the addition of the acidic compound is not particularly limited. From the viewpoint of efficiently obtaining a desired aluminosilicate, the pH is preferably 3 or more, less than 7, and more preferably 3 or more and 5 or less.

The acidic compound to be added in the synthesis step is not particularly limited and may be an organic acid or a mineral acid. Among them, it is preferred to use a mineral acid. Specific examples of the inorganic acid include hydrochloric acid, perchloric acid, and nitric acid. In consideration of the decrease in the coexisting ion species in the solution during the subsequent heat treatment, it is preferred to use an acidic compound which produces the same anion as the anion contained in the aluminum source used.

After the acidic compound is added, heat treatment is performed, whereby it is obtained The desired structure of aluminosilicate.

The heating temperature is not particularly limited. From the viewpoint of efficiently obtaining the desired aluminosilicate, it is preferably from 80 ° C to 160 ° C.

When the heating temperature is 160 ° C or lower, precipitation of diaspore (aluminum hydroxide) tends to be suppressed. Further, when the heating temperature is 80 ° C or higher, the desired synthesis speed of the aluminosilicate is increased, and the desired aluminosilicate is more efficiently produced.

The heating time is not particularly limited. From the viewpoint of obtaining the aluminosilicate having a desired structure more efficiently, it is preferably within 96 hours (4 days).

If the heating time is 96 hours or less, the desired aluminosilicate can be produced more efficiently.

(d) Second cleaning step (desalting and solid separation)

In the second washing step, the obtained one of the heat treatment in the synthesis step is subjected to desalting and solid separation. Thereby, a metal ion adsorbent having excellent metal ion adsorption performance can be obtained. It can be considered, for example, as follows. In other words, in the case where the heat treatment is performed in the synthesis step, the adsorption site of the aluminosilicate is clogged with the coexisting ions, and the desired metal ion adsorption performance cannot be obtained. Therefore, it is considered that the desalting and solid separation are performed by the second washing step of removing at least a part of the coexisting ions from the aluminosilicate obtained in the synthesis step, whereby a metal having excellent metal ion adsorption performance can be obtained. Ion sorbent.

The second washing step may be performed by removing at least a portion of the anion other than the citric acid ion and the cation other than the aluminum ion, and may be before the synthesis step The same operation of the first cleaning step can also be a different operation.

The second washing step is preferably performed such that the concentration of the coexisting ions is equal to or lower than a predetermined concentration. Specifically, for example, when the solid obtained by separating the solid obtained in the second washing step is dispersed in pure water so as to have a concentration of 60 g/L, the conductivity of the dispersion becomes 4.0 S/ It is preferable that the conductivity of the dispersion is 1.0 mS/m or more and 3.0 S/m or less, and more preferably, the conductivity of the dispersion is 1.0 mS/m or more. It is carried out in a manner of 2.0 S/m or less.

When the conductivity of the dispersion is 4.0 S/m or less, there is a tendency that an aluminosilicate having more excellent metal ion adsorption performance is easily obtained.

When the second washing step is carried out using centrifugation, for example, it can be carried out as follows. A base or the like is added to the mixed solution to adjust the pH to 5 to 10. After the pH-adjusted solution was centrifuged, the supernatant solution was discharged to separate the solid as a gel-like precipitate. Then, the solid separated is dispersed again in the solvent. At this time, it is preferable to return to the volume before the centrifugal separation. The dispersion liquid formed by dispersing the solid by separation is centrifuged in the same manner, and the operations of desalting and solid separation are repeated, whereby the concentration of the coexisting ions can be made equal to or lower than a predetermined concentration.

In the second washing step, the pH is adjusted to, for example, 5 to 10, but preferably 8 to 10. The base used for pH adjustment is not particularly limited. For example, sodium hydroxide, ammonia, or the like is preferred.

Further, the conditions of the centrifugal separation are appropriately selected in accordance with the scale of manufacture, the container to be used, and the like. For example, it can be set to room temperature, 1200G or more and 1 minute. Clock ~ 30 minutes. Specifically, for example, when using Suprema 23 manufactured by TOMY Co., Ltd. and the standard rotor NA-16 of the company as a centrifugal separator, it can be set to 3000 rpm (1450 G) or more and 5 minutes to 10 minutes at room temperature.

The solvent in the second washing step can be appropriately selected and used, and it is easy to solvate with the raw material. Specifically, water, ethanol, or the like can be used. However, in terms of reduction of coexisting ions and ease of handling, it is preferred. In order to use water, it is more preferable to use pure water. Further, when the cleaning is repeated a plurality of times, it is preferable to omit the pH adjustment.

The number of treatments for desalting and solid separation in the second washing step may be set according to the amount of residual ions of the coexisting ions, but it is preferably one to six times, and if the washing is repeated three times or more, the metal ion adsorbent is used. The residual amount of the coexisting ions in the medium is sufficiently reduced.

It is preferable that the dispersion liquid after the second washing step has a concentration of chloride ions and sodium ions which are particularly affected by the adsorption performance of the metal ion adsorbent among the remaining coexisting ions. That is, the metal ion adsorbent after washing in the second washing step is preferably such that when the metal ion adsorbent is dispersed in water to prepare an aqueous dispersion having a concentration of 400 mg/L, the concentration is given in the aqueous dispersion. A chloride ion of 100 mg/L or less and a sodium ion of a concentration of 100 mg/L or less. If the chloride ion concentration is 100 mg/L or less and the sodium ion concentration is 100 mg/L or less, the adsorption performance can be further improved. The chloride ion concentration is more preferably 50 mg/L or less, and still more preferably 10 mg/L or less. The sodium ion concentration is more preferably 50 mg/L or less, and still more preferably 10 mg/L or less. Chloride ion concentration and sodium ion concentration can be cleaned by The number of treatments of the step or the type of base used for pH adjustment is adjusted.

Further, the chloride ion concentration and the sodium ion concentration are measured under normal conditions using an ion chromatograph (for example, DX-320 and DX-100 manufactured by Dionex Corporation).

Further, the concentration of the dispersion of the aluminosilicate is based on the mass of the solid obtained by drying the solid at 110 ° C for 24 hours.

In addition, the "dispersion after the second washing step" as used herein refers to a dispersion in which the volume is returned to the volume before the second washing step by the solvent after the second washing step is completed. The solvent to be used can be appropriately selected and used, and it is easy to solvate with a raw material. Specifically, water, ethanol, etc. can be used, but the residual amount of the coexisting ions in the metal ion adsorbent is reduced, and handling is easy. In other words, it is preferred to use water.

The BET specific surface area of the aluminosilicate of the present invention can be adjusted by the treatment method of the second washing step (for example, by repeating one or more times of the following treatment: adding a base to the synthesis solution to adjust the pH to 5 to 10, After centrifugation, the supernatant solution was discharged, and the aluminosilicate remaining as a gelatinous precipitate was again dispersed in a solvent and then returned to the volume before centrifugation to adjust.

In addition, the total pore volume of the aluminosilicate can be adjusted by the treatment method of the second washing step (for example, by repeating one or more times of the following treatment: adding a base to the synthesis solution to adjust the pH to 5 to 10, After centrifugation, the supernatant solution was discharged, and the aluminosilicate remaining as a gelatinous precipitate was again dispersed in a solvent and then returned to the volume before centrifugation to adjust.

In addition, the average pore diameter of the aluminosilicate may be adjusted by the treatment method of the second washing step (for example, by repeating one or more times of the following treatment: adding a base to the synthesis solution to adjust the pH to 5 to 10, After centrifugation, the supernatant solution was discharged, and the aluminosilicate remaining as a gelatinous precipitate was again dispersed in a solvent and then returned to the volume before centrifugation to adjust.

<Metal ion adsorbent>

The metal ion adsorbent of the second embodiment is a metal ion adsorbent containing the above aluminosilicate, and is useful as an adsorbent for metal ions. More specifically, the metal ion adsorbent can be used by applying a metal ion adsorbent to a liquid-permeable honeycomb-shaped substrate or a porous substrate to be used as a filter to adsorb metal ions. The agent is applied to the surface of the granular or spherical substrate and the substrate is filled into a container to use and use the metal ion adsorbent itself. In addition, the base material is not particularly limited, and a natural material such as a metal, a ceramic, a synthetic resin cured product, or wood can be used.

As a specific example of the metal ion, nickel ions, copper ions, manganese ions, and the like are effectively adsorbed.

[Example]

Hereinafter, the present invention will be specifically described by way of examples, but the invention is not limited to the examples.

[Manufacturing Example 1]

<Production of aluminosilicate>

Adding a concentration: 350 mmol/L sodium citrate aqueous solution (500 mL) to a concentration: 700 mmol/L aluminum chloride aqueous solution (500 mL), and stirring Mix for 30 minutes. To the solution, 330 mL of a 1 mol/L sodium hydroxide aqueous solution was added, and the pH was adjusted to 6.1.

After the pH-adjusted solution was stirred for 30 minutes, it was subjected to centrifugation at a rotational speed of 3,000 rpm for 5 minutes using a Suprema 23 and a standard rotor NA-16 as a centrifugal separator. After centrifugation, the supernatant solution was discharged, and the gelatinous precipitate was again dispersed in pure water and returned to the volume before centrifugation. This desalting treatment by centrifugal separation was carried out 3 times.

The gelatinous precipitate obtained after discharging the supernatant of the third desalting treatment was dispersed in pure water at a concentration of 60 g/L, and manufactured by HORIBA: F-55 and conductivity meter: 9382- 10D, the conductivity was measured at room temperature (25 ° C), and the result was 1.3 S/m.

To the gel-like precipitate obtained after discharging the supernatant of the third desalting treatment, 135 mL of a concentration of 1 mol/L hydrochloric acid was added, and the mixture was adjusted to pH = 3.5, followed by stirring for 30 minutes. Using an ICP luminescence spectrometer: P-4010 (manufactured by Hitachi, Ltd.), the concentration of ruthenium atoms and the concentration of aluminum in the solution at this time were measured by a conventional method. As a result, the concentration of ruthenium atoms was 213 mmol/L, and the concentration of aluminum atoms was 426 mmol/L. .

Then, the solution was added to a desiccator and heated at 98 ° C for 48 hours (2 days).

To the heated solution (aluminum citrate concentration: 47 g/L), a concentration of 188 mL of a 1 mol/L sodium hydroxide aqueous solution was added, and the pH was adjusted to 9.1. The aluminosilicate in the solution is agglomerated by pH adjustment, and the aggregate is precipitated by the same centrifugal separation as described above, whereby the supernatant is discharged. Will be in it Desalination treatment was carried out three times by adding pure water to recover the volume before centrifugation.

The gelatinous precipitate obtained after discharging the supernatant of the third desalting treatment was dispersed in pure water at a concentration of 60 g/L, and manufactured by HORIBA: F-55 and conductivity meter: 9382- 10D, the conductivity was measured at room temperature (25 ° C), and the result was 0.6 S/m.

The gelatinous precipitate obtained after discharging the supernatant of the third desalting treatment at 60 ° C was dried for 16 hours to obtain 30 g of a powder. This powder was designated as sample A.

<BET specific surface area, total pore volume, average pore diameter>

The BET specific surface area, total pore volume, and average pore diameter of the sample A were measured based on the nitrogen adsorption performance. The evaluation device was manufactured by QUANTACHROME Co., Ltd.: AUTOSORB-1 (trade name). When these measurements were performed, the evaluation temperature was 77 K after the pretreatment of the sample described later, and the evaluation pressure range was set to less than 1 with respect to the relative pressure (balance pressure with respect to the saturated vapor pressure).

As a pretreatment, the measurement unit to which the sample A of 0.05 g was charged was degassed and heated by automatic control using a vacuum pump. The detailed conditions of this treatment are set such that after the pressure is reduced to 10 Pa or less, the mixture is heated at 110 ° C for 3 hours or more, and then maintained in a reduced pressure state and naturally cooled to normal temperature (25 ° C).

As a result of the evaluation, Sample A had a BET specific surface area of 363 m ² /g, a total pore volume of 0.22 cm ³ /g, and an average pore diameter of 2.4 nm.

<Powder X-ray diffraction>

Powder X-ray diffraction was carried out using a Geigerflex RAD-2X (trade name) manufactured by Rigaku Co., Ltd., and using CuKα rays as an X-ray source. The spectrum of the powder X-ray diffraction of the sample A is shown in Fig. 1. A broad peak was observed around 2θ = 26.9° and around 40.3°. Further, sharp peaks were observed in the vicinity of 2θ = 18.8°, 20.3°, 27.8°, 40.6°, and 53.3°.

< ²⁷ Al-NMR>

The AV400WB type manufactured by Bruker BioSpin was used as a measuring device for ²⁷ Al-NMR spectrum, and the measurement was performed under the following conditions.

Resonance frequency: 104MHz

Determination method: MAS (single pulse)

MAS speed: 10kHz

Measurement area: 52 kHz

Data points: 4096

Resolution (measurement area / data points): 12.7 Hz

Pulse width: 3.0μsec

Delay time: 2 seconds

Chemical shift value benchmark: α-alumina 3.94ppm

Window function: exponential function

Line broadening factor: 10Hz

The spectrum of ²⁷ Al-NMR of Sample A is shown in Fig. 2 . As shown in Fig. 2, there is a peak near 3 ppm. In addition, several peaks were observed around 55 ppm. The area ratio of the peak near 55 ppm to the peak near 3 ppm was 15%.

< ²⁹ Si-NMR>

The AV400WB type manufactured by Bruker BioSpin was used as a ²⁹ Si-NMR spectrum measuring apparatus, and the measurement was performed under the following conditions.

Resonance frequency: 79.5MHz

Determination method: MAS (single pulse)

MAS speed: 6kHz

Measurement area: 24 kHz

Number of data points: 2048

Resolution (measurement area / data points): 5.8 Hz

Pulse width: 4.7μsec

Delay time: 600 seconds

Chemical shift value reference: TMSP-d ₄ (3-(trimethylsulfonyl) (2,2,3,3- ² H ₄ )propionate) 1.52 ppm

Window function: exponential function

Line broadening factor: 50Hz

The spectrum of ²⁹ Si-NMR of Sample A is shown in Fig. 3 . As shown in Fig. 3, there are peaks in the vicinity of -78 ppm and in the vicinity of -85 ppm. The area of the peak near -78 ppm and -85 ppm was measured by the above method. As a result, when the area of the peak A of -78 ppm was 1.00, the area of the peak B of -85 ppm was 2.61.

<Element ratio Si/Al>

The elemental ratio of Si and Al determined by ICP emission spectroscopic analysis (ICP emission spectrometer: P-4010 (manufactured by Hitachi, Ltd.)) according to a conventional method was 0.5.

<Transmission electron microscope (TEM) photo observation>

A transmission electron microscope (TEM) photograph when the sample A was observed at 100,000 times is shown in Fig. 4 . Further, the TEM observation was carried out using a transmission electron microscope (manufactured by Hitachi High-Technologies Co., Ltd., model H-7100FA) at an acceleration voltage of 100 kV. Further, Sample A of the TEM observation target was prepared in the following manner. That is, the heated solution (aluminum citrate concentration of 47 g/L) was diluted to 10 times with pure water before the final demineralization treatment step, and subjected to ultrasonic irradiation treatment for 5 minutes, and added to TEM observation. Sample A was prepared by subjecting the sample preparation support to natural drying to form a film.

As shown in Fig. 4, there is no tube having a length of 50 nm or more.

<Metal ion adsorption performance>

The evaluation of the metal ion adsorption performance was carried out by ICP emission spectrometry (ICP emission spectrometer: P-4010 (manufactured by Hitachi, Ltd.)).

In order to evaluate the metal ion adsorption performance, first, for each of the metal sulphate and pure water, Ni ²⁺ or Mn ^{2+ was} used to prepare a 100 ppm metal ion solution. Sample A was added to the preparation solution so that the sample A became 1.0% by mass, and the mixture was thoroughly mixed and allowed to stand. Then, the concentration of each metal ion before and after the addition of the sample A was measured by ICP emission spectrometry.

Regarding the metal ion adsorption performance, after the sample A was added, the concentration of Ni ²⁺ was less than 5 ppm, and the concentration of Mn ²⁺ was 10 ppm.

[Comparative Example 1]

Commercially available activated carbon (manufactured by Wako Pure Chemical Industries, Ltd., activated carbon, broken form, 2 mm to 5 mm) was used as sample B. Regarding the metal ion adsorption performance, when Sample B was added, the concentration of Ni ²⁺ became 50 ppm, and the concentration of Mn ²⁺ became 60 ppm.

[Comparative Example 2]

Commercially available silicone (manufactured by Wako Pure Chemical Industries, Ltd., small granular (white)) was used as sample C. Regarding the metal ion adsorption performance, after the sample C was added, the concentration of Ni ²⁺ became 100 ppm, and the concentration of Mn ²⁺ became 100 ppm.

[Comparative Example 3]

Commercially available zeolite 4A (manufactured by Wako Pure Chemical Industries, Ltd., Molecular sieves 4A) was used as sample D. Regarding the metal ion adsorption performance, when Sample D was added, the concentration of Ni ²⁺ became 30 ppm, and the concentration of Mn ²⁺ became 10 ppm.

Further, when the Mn ²⁺ solution to which the zeolite 4A was added was allowed to stand, the turbidity was brown.

[Manufacturing Example 2]

<Production of aluminosilicate>

Adding a concentration: 74 mmol/L sodium citrate aqueous solution (500 mL) to a concentration: 180 mmol/L aluminum chloride aqueous solution (500 mL), and stirring 30 minutes. To the solution, 93 mL of a 1 mol/L sodium hydroxide aqueous solution was added, and the pH was adjusted to 7.0.

After the pH-adjusted solution was stirred for 30 minutes, it was subjected to centrifugation at a rotational speed of 3,000 rpm for 5 minutes using a Suprema 23 and a standard rotor NA-16 as a centrifugal separator. After centrifugation, the supernatant solution was discharged, and the gelatinous precipitate was again dispersed in pure water and returned to the volume before centrifugation. This desalting treatment by centrifugal separation was carried out 3 times.

The gelatinous precipitate obtained after discharging the supernatant of the third desalting treatment was adjusted to have a concentration of 60 g/L, and manufactured by HORIBA: F-55 and conductivity meter: 9382-10D at room temperature (25). The conductivity was measured at ° C) and found to be 1.3 S/m.

Pure water was added to the gel-like precipitate obtained after the supernatant of the third desalting treatment, and the volume was changed to 12 L. To the solution, 60 mL of hydrochloric acid having a concentration of 1 mol/L was added, and adjusted to pH = 4.0, followed by stirring for 30 minutes. The ICP emission spectrometer: P-4010 (manufactured by Hitachi, Ltd.) was used to measure the concentration of ruthenium atoms and the concentration of aluminum in the solution at this time. As a result, the concentration of ruthenium atoms was 2 mmol/L, and the concentration of aluminum atoms was 4 mmol/L.

Then, the solution was added to a desiccator and heated at 98 ° C for 96 hours (4 days).

To the heated solution (aluminum citrate concentration: 0.4 g/L), 60 mL of a 1 mol/L sodium hydroxide aqueous solution was added, and the pH was adjusted to 9.0. The solution is agglomerated by pH adjustment, the aggregate is precipitated by centrifugation, and then the aggregate is sedimented by the same centrifugal separation as the first washing step. The lake is thereby discharged. The desalting treatment in which pure water was added thereto to recover the volume before centrifugation was performed 3 times.

The gelatinous precipitate obtained after discharging the supernatant of the third desalting treatment was adjusted to have a concentration of 60 g/L, and manufactured by HORIBA: F-55 and conductivity meter: 9382-10D at room temperature (25). The conductivity was measured at ° C) and found to be 0.6 S/m.

The gelatinous precipitate obtained after the desalting treatment was dried at 60 ° C for 72 hours (3 days) to obtain 4.8 g of a powder. This powder was designated as sample E.

<BET specific surface area, total pore volume, average pore diameter>

The BET specific surface area, the total pore volume, and the average pore diameter were measured in accordance with the nitrogen adsorption performance in the same manner as in Production Example 1.

As a result of the evaluation, the BET specific surface area of the sample E was 323 m ² /g, the total pore volume was 0.22 cm ³ /g, and the average pore diameter was 2.7 nm.

<Powder X-ray diffraction>

Powder X-ray diffraction of the sample E was carried out in the same manner as in Production Example 1. The spectrum of the powder X-ray diffraction of the sample E is shown in Fig. 1. It has a broad peak around 2θ=4.8°, 9.7°, 14.0°, 18.3°, 27.3°, and 40.8°.

< ²⁷ Al-NMR>

The spectrum of ²⁷ Al-NMR of Sample E is shown in Fig. 2 . As shown in Fig. 2, there is a peak near 3 ppm. In addition, several peaks were observed around 55 ppm. The area ratio of the peak near 55 ppm to the peak near 3 ppm was 4%.

< ²⁹ Si-NMR>

The spectrum of ²⁹ Si-NMR of Sample E is shown in Fig. 3 . As shown in Fig. 3, there are peaks in the vicinity of -78 ppm and -85 ppm. The area of the peak near -78 ppm and -85 ppm was measured by the above method. As a result, when the area of the peak A in the vicinity of -78 ppm was 1.00, the area of the peak B in the vicinity of -85 ppm was 0.44.

<Element ratio Si/Al>

The elemental ratio of Si and Al determined by ICP emission spectroscopic analysis (ICP emission spectrometer: P-4010 (manufactured by Hitachi, Ltd.)) according to a conventional method was 0.5.

<Transmission electron microscope (TEM) photo observation>

A transmission electron microscope (TEM) photograph when the sample E was observed at 100,000 times by the same method as in Example 1 is shown in Fig. 5. As shown in Fig. 5, a tubular material is produced, and the tubular body 10a has a length in the longitudinal direction of the tube portion of about 1 nm to 10 μm, an outer diameter of about 1.5 nm to 3.0 nm, and an inner diameter of about 0.7 nm to 1.4 nm.

<Metal ion adsorption performance>

The Mn ²⁺ ion adsorption performance was evaluated in the same manner as in Production Example 1. As a result, Sample E showed the same metal ion adsorption performance as Sample A.

[Metal ion adsorption performance evaluation 1]

The metal ion adsorption performance was evaluated by the method described in Production Example 1 except that the sample A produced in Production Example 1 was used, and the amount of the sample A was changed as shown in the following table. The results are shown in the table below.

As shown in the above table, when 0.5% by mass of the sample A was added, the manganese ion concentration was halved. Moreover, when 2.0% by mass of Sample A was added, 95% of manganese ions were trapped.

[Metal ion adsorption performance evaluation 2]

The metal ion adsorption performance was evaluated by the method described in Production Example 1 except that the sample A prepared in Production Example 1 was replaced with Cu ²⁺ and the metal ion concentration was changed to 400 ppm. . The pH at this time was 5.1. After the addition of the sample A, the concentration of Cu ²⁺ became 160 ppm.

All the contents disclosed in Japanese Patent Application No. 2011-054787, Japanese Patent Application No. 2011-054788, Japanese Patent Application No. 2011-054857, and Japanese Patent Application No. 2011-054858 are incorporated herein by reference. in. All of the documents, patent applications, and technical specifications described in the specification are the same as those which are specifically and independently described in reference to each document, patent application, and technical specification. In this manual.

10a‧‧‧Body

20‧‧‧ inner wall

30‧‧‧ gap

Fig. 1 is a powder X-ray diffraction spectrum of the aluminosilicate of the present embodiment.

Fig. 2 is a ²⁷ Al-NMR spectrum of the aluminosilicate of the present embodiment.

Fig. 3 is a ²⁹ Si-NMR spectrum of the aluminosilicate of the present embodiment.

Fig. 4 is a transmission electron microscope (TEM) photograph of the aluminosilicate of the present embodiment.

Figure 5 is a transmission electron microscope (TEM) photograph of so-called filamentous aragonite.

Fig. 6 is a view schematically showing a tubular so-called filamentous aragonite according to the present embodiment.

Claims (21)

An aluminosilicate having an elemental ratio of Si and Al of 0.3 to 1.0 in terms of molar ratio of Si/Al, a peak near 3 ppm in a ²⁷ Al-NMR spectrum, and -78 ppm in a ²⁹ Si-NMR spectrum. And a peak near -85 ppm, having a peak near 2θ=26.9° and 40.3° in a powder X-ray diffraction spectrum using CuKα ray as an X-ray source, and a peak A near -78 ppm in a ²⁹ Si-NMR spectrum The area ratio (peak B/peak A) of the peak B near -85 ppm is 2.0 to 9.0. The aluminosilicate described in claim 1, wherein when viewed in a transmission electron microscope (TEM) photograph at 100,000 times, there is no tube having a length of 50 nm or more. An aluminosilicate having an elemental ratio of Si and Al of 0.3 to 1.0 in terms of molar ratio of Si/Al, ²⁷ Al-NMR spectrum having a peak near 3 ppm, and a ²⁹ Si-NMR spectrum near -78 ppm and around -85 ppm A powder X-ray diffraction spectrum having a peak with CuKα ray as an X-ray source has a peak near 2θ=26.9° and 40.3°, and does not exist when observed in a transmission electron microscope (TEM) photograph at 100,000 times. A tube having a length of 50 nm or more. The aluminosilicate according to any one of the items 1 to 3, wherein the BET specific surface area is 250 m ² /g or more, the total pore volume is 0.1 cm ³ /g or more, and the average pore diameter is It is 1.5 nm or more. The aluminosilicate according to any one of claims 1 to 3, wherein in the powder X-ray diffraction spectrum, at 2θ = 18.8°, 20.3°, 27.8°, 40.6° and 53.3° There are more crests nearby. A metal ion adsorbent comprising aluminum alumite as a component, the elemental ratio of Si and Al is 0.3 to 1.0 in terms of molar ratio of Si/Al, and about 3 ppm in ²⁷ Al-NMR spectrum. An aluminosilicate having a peak and having a peak near -78 ppm and around -85 ppm in a ²⁹ Si-NMR spectrum, wherein peaks A and -85 ppm in the vicinity of -78 ppm in the ²⁹ Si-NMR spectrum of the above aluminosilicate The area ratio (peak B/peak A) of the nearby peak B is 2.0 to 9.0. A metal ion adsorbent comprising aluminum alumite as a component, the elemental ratio of Si and Al is 0.3 to 1.0 in terms of molar ratio of Si/Al, and about 3 ppm in ²⁷ Al-NMR spectrum. An aluminosilicate having a peak and having a peak near -78 ppm and around -85 ppm in a ²⁹ Si-NMR spectrum, wherein the aluminosilicate is 100,000 times in a transmission electron microscope (TEM) photograph When observed, there was no aluminosilicate of a tubular having a length of 50 nm or more. The metal ion adsorbent according to claim 6 or 7, wherein the aluminosilicate has a BET specific surface area of 250 m ² /g or more, a total pore volume of 0.1 cm ³ /g or more, and an average fineness. The pore diameter is 1.5 nm or more. The metal ion adsorbent according to claim 6 or 7, wherein the aluminosilicate is in a powder X-ray diffraction spectrum using CuKα rays as an X-ray source at 2θ=26.9° and 40.3. Aluminosilicate with a peak near °. The metal ion adsorbent according to claim 9, wherein the aluminosilicate is in the powder X-ray diffraction spectrum at 2θ There are more peaks near=18.8°, 20.3°, 27.8°, 40.6° and 53.3°. A method for producing an aluminosilicate according to any one of claims 1 to 5, which comprises: (a) mixing a solution containing ceric acid ions and a solution containing aluminum ions to obtain a reaction (b) Desalting and solid separation of the above reaction product; (c) concentration in an aqueous medium in the presence of an acid with a cesium atom concentration of 100 mmol/L or more and an aluminum atom concentration of 100 mmol/L or more The conditions are heat-treated in the case where the solid is separated in the above step (b); and (d) the salt-removal and solid-separation are carried out in the case where the heat treatment is carried out in the above step (c). The method for producing an aluminosilicate according to the invention of claim 11, wherein the conductivity in the step (b) is 4.0S when dispersed in water at a concentration of 60 g/L. /m below. The method for producing an aluminosilicate according to claim 11, wherein the step (c) is to adjust the pH to 3 or more, less than 7, and at a temperature of 80 to 160 ° C within 96 hours. The step of heat treatment is performed during the period. The method for producing an aluminosilicate according to claim 11, wherein the step (a) is a solution of the above-mentioned aluminum ion-containing solution having a ruthenium atom concentration of the solution containing ruthenium ions of 100 mmol/L or more. The aluminum atom concentration is 100 mmol/L or more, and the lanthanum is a step in which the element of aluminum is mixed with Si/Al in a molar ratio of 0.3 to 1.0. The method for producing an aluminosilicate according to the invention of claim 11, wherein the step (b) comprises: dispersing the reaction product in an aqueous medium to obtain a dispersion; and adjusting the pH of the dispersion The steps of 5 to 7 and solid separation are carried out. A method for producing a metal ion adsorbent according to any one of claims 6 to 10, which comprises: (a) mixing a solution containing ceric acid ions and a solution containing aluminum ions to obtain a reaction a product; (b) desalting and solid separation of the above reaction product; (c) heat-treating the solid separated in the above step (b) in the presence of an acid in an aqueous medium; and (d) The salt obtained by the heat treatment in the above step (c) is subjected to desalting and solid separation. The method for producing a metal ion adsorbent according to claim 16, wherein the heat treatment in the step (c) is a concentration of germanium atoms in an aqueous medium of 100 mmol/L or more and an aluminum atom concentration of 100 mmol/L. The above concentration conditions are carried out. The method for producing a metal ion adsorbent according to claim 16, wherein the conductivity in the step (b) is 4.0S when dispersed in water at a concentration of 60 g/L. /m below. Such as the metal ion adsorbent described in claim 16 In the production method, the step (c) is a step of adjusting the pH to 3 or more and less than 7, and performing heat treatment in a period of 96 hours or less at a temperature of 80 ° C to 160 ° C. The method for producing a metal ion adsorbent according to claim 16, wherein the step (a) is a solution of the above-mentioned aluminum ion-containing solution having a cerium atom concentration of the solution containing ceric acid ions of 100 mmol/L or more. The aluminum atomic concentration is 100 mmol/L or more, and the element of aluminum is mixed with a solution containing a ceric acid ion and a solution containing aluminum ions so that the element ratio of aluminum to Si/Al is 0.3 to 1.0 in terms of a molar ratio. The method for producing a metal ion adsorbent according to claim 16, wherein the step (b) comprises: dispersing the reaction product in an aqueous medium to obtain a dispersion; and adjusting the pH of the dispersion The steps of 5 to 7 and solid separation are carried out.